Seismic anisotropy and mantle flow beneath East Africa and Arabia

Abstract

Neoteric geodynamic models have revealed a variety of mantle processes, yet the predicted relationship between the mantle flow and seismic anisotropy remains enigmatic. This ambiguity is caused by the implementation of different tomographic models, viscosity calculations, and the lack of a homogeneous database of shear-wave splitting (SWS) parameters. In this study, I conducted continental scale SWS measurements using data recorded by 285 stations to constrain similarities and difference between the observed the SWS and the calculated ones by recent geodynamical studies in East Africa and Arabia. A comparison of the SWS measurements with previous results of geodynamic modeling suggests that a combination of NNE oriented flow field related to the motion and the subduction of the African/Arabian plates beneath Eurasia over the past 150 Ma are mostly responsible for the seismic anisotropy patterns. These new findings can help eliminate some of the discrepancies among geodynamical studies.